Picked up an old Back Bar unit for dirt cheap but it's a bit of a basket case. The various fans run but the compressor doesn't kick on. There's pressure in the lines so at the very least there is some coolant. The wiring is a mess and there's nothing electrical connected to the compressor. I'll attach a few pictures here. There's the overload, starter relay, and a cap but I don't see anything that would connect to the 3 prongs on the compressor. Any idea's what I'm missing?

The connector to the compressor. It has 3 prongs which I have seen described as a fusite connection. I have a power cord connected to a starter relay and overload protector but nothing was wired to the compressor itself. Most images of this compressor show a cover or box below the cap; I'm assuming the relay and overload would normally sit in there.

Since stuff is just dangling there now, replacing it all with a single unit sounds great. However, I'm not sure what you meant by the distinction between electronic starters and hard start. Most of the stuff listed on those two pages refer to giving a boost for hard start.

Ok, gotcha. It doesn't look like any of those have a fusite connection but I'll just have to figure something out on that end of things.

Is there any particular reason to stay away from the hard-start models? It seems like they're designed to give an extra bit of starting power beyond the OEM cap. This compressor is 14 years old and there's a good chance it won't start at all although nothing is ground out and the terminals all have continuity between each other.

Ahh, my bad, my monitor at home is a bit washed out and I didn't see the pin holes in those parts. So based on all that, it looks like my best bet is a PRO41. Looks pretty easy to install.

Two followups:

First, since the 3 prongs are symmetrical, is there an easy way to figure out which is the common, run, and start terminals? My guess is just figure it out by the different resistance between them: lowest would be run, next would be start, and last would be run to start.

Second, when asked about an appropriate cap replacement, RepairClinic simply stated that they do not carry parts for my model. I gave them the compressor model as well as the cap's part number (85PS110C90) and relevant details (110v 60hz 145-175MFD). I didn't expect them to by model, but they have 500 caps, likely one of them would work but there's no good way of finding them by the relevant details. Think they'd have one or do I just need to look elsewhere? Thanks again for you help.

Welp, almost 4 months later and the room this is going in is almost ready to paint. Time to get this working or toss it. I replaced the relay and run capacitor but the compressor is shot.

A question about replacing the compressor. The direct replacement still exists but is r12. I'm assuming I would have to convert it to r134 so should I look for a different compressor model specifically designed for r134?